Field of the Invention
This invention relates to new amphoteric surfactants, and more particularly to specific ethyoxylated amines which are quaternized and at least partially phosphated; methods of making such surfactants; and to methods of using such surfactants. More particularly, this invention relates to novel complex phosphate surfactants that are derived from quaternary dihydroxy compounds of the formula ##STR2## WHEREIN R and R.sub.1 represent the same or different alkyl moieties containing 1 to 22 carbon atoms, the sum of R and R.sub.1 not being less than 7 carbon atoms; R.sub.2 and R.sub.3 each represent H or CH.sub.3 ; n is an integer having an average value of from 1 to 50; X represents an anion of halogen, sulfate, or alkyl sulfate; and wherein the resultant complex phosphate ester contains at least 1/3P atom per mole of quaternary dihydroxy compound; can be made through reaction (phosphating) of such dihydroxy quaternary compound with a conventional phosphating agent such as P.sub.2 O.sub.5, polyphosphoric acid, or POCl.sub.3 to form amphoteric surface active agents having utility as metal lubricants, heavy duty cleaners, detergents, etc.
In particular, the ultimate complex phosphate ester surfactants themselves, that are derived from phosphating in the manner discussed above, are compositions which are characterized by the following chemical formula or structure ##STR3## wherein R and R.sub.1 represent the same or different alkyl moieties containing 1 to 22 carbon atoms, the sum of the total number of carbon atoms for R and R.sub.1 not being less than 7; R.sub.2 and R.sub.3 each represent H or CH.sub.3 ; n is an integer having an average value of from 1 to 50; ##STR4## where R.sub.2 and R.sub.3 are as previously defined; Y is a moiety of OH, ##STR5## (a triester), p being an integer of at least 1, M being H or a metal cationic equivalent thereof such as that of Na or K and being as previously defined; Z is a moiety of OH, ##STR6## p being an integer of at least 1, M being a metal cationic equivalent thereof (e.g., Na or K) and L being as previously defined; and X is an anion such as, e.g., halogen, sulfate, or alkyl sulfate, etc. Of course, as would be appreciated by those skilled in the art, the diesters and triesters of the above formula can exist in a variety of forms, e.g., in the form of a variety of aliphatic, cyclic, and polymeric compounds. However, in accordance with the present invention, the major products formed comprise aliphatic monoesters and diesters.
Description of the Prior Art
The prior art describes many, and varied, types of amine phosphonates, phosphates, and related compounds. For example, various hydroxy alkyl and dihydroxyl alkyl derivatives of higher fatty acid amines have been phosphated, but none of these compounds have achieved significant commercial acceptance and in none have been found all of the desirable properties of the instant invention.
Considerable research has been carried out during the past few years directed towards improving the lubricating and rust and corrosive inhibiting properties of the new synthetic surfactant compositions. Most of these surfactant compositions have, as active surfactant ingredient, anionic ions. As representative of the various additives which have been employed for improving the detersive and surfactant properties of such anionic compositions, there may be mentioned alkali metal phosphates, borates, carbonates, sulfates, chlorides, silicates, higher aliphatic alcohols such as lauryl alcohol, and higher fatty acid amides and alkylol amides such as lauroyl amide, lauroyl mono and dialkyl amides, lauroyl ethanolamide, and lauroyl di-ethanolamide. The use of the aforementioned alkali metal salts, particularly the phosphates and borates, generally have resulted in what is known as built or heavy duty type detergents. While such compositions are partially suitable for use in cleaning machines of various types, they find limited use in applications wherein any degree of metal lubrication and cleaning is involved. However, these additives, which have thus far been more or less commercially accepted have properties and characteristics which still leave much to be desired with respect to characteristics such as more universal compatibility and adaptability to different conditions, cost and the like.
Various organic surfactants have achieved considerable commercial success; however, the art is still confronted by the problem of providing surfactant compositions which provide dual cationic and anionic functionalities and yet are free from undesirable disadvantages.
It has been found that the compositions according to the instant invention comprise very valuable surface-active agents which may be used either alone or admixed with other cationic, anionic or non-ionic surface active agents in the different fields as above referred to.
The instant compositions comprise a very valuable group of surface-active agents, known as amphoteric compounds, i.e., chemical agents containing both cationic and anionic groups in a single molecule, and therefore exhibit a high degree of stability and remarkable utility in concentrated electrolytic solutions. These compounds also show unusual chemical stability under prolonged contact with alkaline systems. Products made from the instant compounds have the following advantages: they possess good surface-active properties so that they can be used as detergents since they have the advantage of preventing the accumulation of electrostatic charges, are well tolerated by the skin and, therefore, do not cause any appreciable irritation thereto, are useful as lubricants, rust inhibitors, corrosion inhibitors, hard surface cleaners, alkali soluble cleaners, agriculture emulsifiers, hydraulic fluids, and in emulsion polymerization.
These amphoterics employ the phosphate ester as the anionic moiety, thereby in addition to providing dual cationic/anionic functionality, offer novel properties such as metal lubrication, and cleaning, enhanced corrosion inhibition and alkali solubility.
The novel compounds of this invention have the following unexpected combinations of properties: (1) they, unlike phosphates of ethoxylated amines, tolerate the presence of chlorine bleaches; (2) they may be used in shampoos and other cosmetics at pH values of 4.5-8.5 and under these conditions are effective cleaning agents whereas conventional counterparts to these materials do not work well under pH values of 6.0:conventional amphoterics such as betaines do not work at their isoelectric point (about pH 5.7) since they become insoluble at these pH values; (3) they are better detergents with average or hard water; do not precipitate; at pHs as low as 4.5 they are mild to the eyes and skin and they are relatively non-toxic. In addition, these products are readily biodegradable and as such are ecologically safe. The instant amphoteric compounds are useful as detergents, wetting, emulgating and emulsifying agents and also possess a unique combination of properties which will provide new and improved products for lubricants, pesticide emulsifiers, hard surface cleaners, etc. They are also useful as surface active agents in treating natural and synthetic fibers in the textile and related fields where they may be employed as synthetic detergents, dye assistants and softeners.
These amphoteric surfactants also show an advantage over the prior art and seemingly do not exhibit a pronounced isoelectric point where general surface-active and physical properties such as solubility, foaming, etc. are at a minimum.